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Example: Configuring an IS-IS Default Route Policy on Logical Systems
This example shows logical systems configured on a single physical router and explains how to configure a default route on one logical system.
Requirements
No special configuration beyond device initialization is required before configuring this example.
Overview
This example shows a logical system redistributing a default route to other logical systems. All logical systems are running IS-IS. A common reason for a default route is to provide a path for sending traffic destined outside the IS-IS domain.
In this example, the default route is not used for forwarding
traffic. The no-install statement prevents the route from
being installed in the forwarding table of Logical System LS3. If
you configure a route so it is not installed in the forwarding table,
the route is still eligible to be exported from the routing table
to other protocols. The discard statement silently drops
packets without notice.
Configuration
CLI Quick Configuration
To quickly configure this example, copy the
following commands, paste them into a text file, remove any line breaks,
change any details necessary to match your network configuration,
copy and paste the commands into the CLI at the [edit] hierarchy
level, and then enter commit from configuration mode.
set logical-systems LS3 interfaces lt-1/2/0 unit 3 description LS3->LS2 set logical-systems LS3 interfaces lt-1/2/0 unit 3 encapsulation ethernet set logical-systems LS3 interfaces lt-1/2/0 unit 3 peer-unit 4 set logical-systems LS3 interfaces lt-1/2/0 unit 3 family inet address 10.0.2.1/30 set logical-systems LS3 interfaces lt-1/2/0 unit 3 family iso set logical-systems LS3 interfaces lt-1/2/0 unit 5 description LS3->LS1 set logical-systems LS3 interfaces lt-1/2/0 unit 5 encapsulation ethernet set logical-systems LS3 interfaces lt-1/2/0 unit 5 peer-unit 0 set logical-systems LS3 interfaces lt-1/2/0 unit 5 family inet address 10.0.1.1/30 set logical-systems LS3 interfaces lt-1/2/0 unit 5 family iso set logical-systems LS3 interfaces lo0 unit 3 family iso address 49.0001.1234.1600.2231.00 set logical-systems LS3 protocols isis export isis-default set logical-systems LS3 protocols isis interface lt-1/2/0.3 set logical-systems LS3 protocols isis interface lt-1/2/0.5 set logical-systems LS3 protocols isis interface lo0.3 passive set logical-systems LS3 routing-options static route 0.0.0.0/0 discard set logical-systems LS3 routing-options static route 0.0.0.0/0 no-install set logical-systems LS3 policy-options policy-statement isis-default from protocol static set logical-systems LS3 policy-options policy-statement isis-default from route-filter 0.0.0.0/0 exact set logical-systems LS3 policy-options policy-statement isis-default then accept
Procedure
Step-by-Step Procedure
The following example requires you to navigate various levels in the configuration hierarchy. For information about navigating the CLI, see Using the CLI Editor in Configuration Mode in the CLI User Guide.
To configure an IS-IS default route policy on logical systems:
Configure the logical tunnel interfaces.
[edit logical-systems LS3 interfaces lt-1/2/0] user@R1# set unit 3 description LS3->LS2 user@R1# set unit 3 encapsulation ethernet user@R1# set unit 3 peer-unit 4 user@R1# set unit 3 family inet address 10.0.2.1/30 user@R1# set unit 3 family iso user@R1# set unit 5 description LS3->LS1 user@R1# set unit 5 encapsulation ethernet user@R1# set unit 5 peer-unit 0 user@R1# set unit 5 family inet address 10.0.1.1/30 user@R1# set unit 5 family iso [edit logical-systems LS3 interfaces lo0 unit 3] user@R1# set family iso address 49.0001.1234.1600.2231.00
Enable IS-IS on the interfaces.
[edit logical-systems LS3 protocols isis] user@R1# set interface lt-1/2/0.3 user@R1# set interface lt-1/2/0.5 user@R1# set interface lo0.3 passive
Configure the default route on Logical System LS3.
[edit logical-systems LS3 routing-options] user@R1# set static route 0.0.0.0/0 discard user@R1# set static route 0.0.0.0/0 no-install
Configure the default route policy on Logical System LS3.
[edit logical-systems LS3 policy-options] user@R1# set policy-statement isis-default from protocol static user@R1# set policy-statement isis-default from route-filter 0.0.0.0/0 exact user@R1# set policy-statement isis-default then accept
Apply the export policy to IS-IS on Logical System LS3.
[edit logical-systems LS3 protocols isis] user@R1# set export isis-default
If you are done configuring the device, commit the configuration.
[edit] user@R1# commit
Results
From configuration mode, confirm your configuration by issuing
the show logical-systems LS3 command. If the output does
not display the intended configuration, repeat the instructions in
this example to correct the configuration.
user@R1# show logical-systems LS3
interfaces {
lt-1/2/0 {
unit 3 {
description LS3->LS2;
encapsulation ethernet;
peer-unit 4;
family inet {
address 10.0.2.1/30;
}
family iso;
}
unit 5 {
description LS3->LS1;
encapsulation ethernet;
peer-unit 0;
family inet {
address 10.0.1.1/30;
}
family iso;
}
}
lo0 {
unit 3 {
family iso {
address 49.0001.1234.1600.2231.00;
}
}
}
}
protocols {
isis {
export isis-default;
interface lt-1/2/0.3;
interface lt-1/2/0.5;
interface lo0.3 {
passive;
}
}
}
policy-options {
policy-statement isis-default {
from {
protocol static;
route-filter 0.0.0.0/0 exact;
}
then accept;
}
}
routing-options {
static {
route 0.0.0.0/0 {
discard;
no-install;
}
}
}
}
Verification
Confirm that the configuration is working properly.
Verifying That the Static Route Is Redistributed
Purpose
Make sure that the IS-IS policy is working by checking the routing tables.
Action
user@R1> show route logical-system LS3
inet.0: 6 destinations, 6 routes (6 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
0.0.0.0/0 *[Static/5] 00:00:45
Discard
10.0.0.0/30 *[IS-IS/15] 1w0d 10:14:14, metric 20
to 10.0.2.2 via lt-1/2/0.3
> to 10.0.1.2 via lt-1/2/0.5
10.0.1.0/30 *[Direct/0] 1w0d 10:15:18
> via lt-1/2/0.5
10.0.1.1/32 *[Local/0] 1w0d 10:15:18
Local via lt-1/2/0.5
10.0.2.0/30 *[Direct/0] 1w0d 10:15:18
> via lt-1/2/0.3
10.0.2.1/32 *[Local/0] 1w0d 10:15:18
Local via lt-1/2/0.3
iso.0: 1 destinations, 1 routes (1 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
49.0001.1234.1600.2231/72
*[Direct/0] 1w0d 10:17:19
> via lo0.3user@R1> show route logical-system LS2
inet.0: 6 destinations, 6 routes (6 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
0.0.0.0/0 *[IS-IS/160] 00:01:38, metric 10
> to 10.0.2.1 via lt-1/2/0.4
10.0.0.0/30 *[Direct/0] 1w0d 10:16:11
> via lt-1/2/0.1
10.0.0.2/32 *[Local/0] 1w0d 10:16:11
Local via lt-1/2/0.1
10.0.1.0/30 *[IS-IS/15] 1w0d 10:15:07, metric 20
> to 10.0.0.1 via lt-1/2/0.1
to 10.0.2.1 via lt-1/2/0.4
10.0.2.0/30 *[Direct/0] 1w0d 10:16:11
> via lt-1/2/0.4
10.0.2.2/32 *[Local/0] 1w0d 10:16:11
Local via lt-1/2/0.4
iso.0: 1 destinations, 1 routes (1 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
49.0001.1720.1600.2002/72
*[Direct/0] 1w0d 10:18:12
> via lo0.2user@R1> show route logical-system LS1
inet.0: 6 destinations, 6 routes (6 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
0.0.0.0/0 *[IS-IS/160] 00:02:01, metric 10
> to 10.0.1.1 via lt-1/2/0.0
10.0.0.0/30 *[Direct/0] 1w0d 10:16:34
> via lt-1/2/0.2
10.0.0.1/32 *[Local/0] 1w0d 10:16:34
Local via lt-1/2/0.2
10.0.1.0/30 *[Direct/0] 1w0d 10:16:34
> via lt-1/2/0.0
10.0.1.2/32 *[Local/0] 1w0d 10:16:34
Local via lt-1/2/0.0
10.0.2.0/30 *[IS-IS/15] 1w0d 10:15:55, metric 20
to 10.0.1.1 via lt-1/2/0.0
> to 10.0.0.2 via lt-1/2/0.2
iso.0: 1 destinations, 1 routes (1 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
49.0001.1720.1600.1001/72
*[Direct/0] 1w0d 10:18:35
> via lo0.1Meaning
The routing table on Logical System LS3 contains the
default 0.0.0.0/0 route from protocol Static. The routing tables on Logical System LS1 and Logical System LS2
contain the default 0.0.0.0/0 route from protocol IS-IS. If Logical System LS1 and Logical System LS2 receive packets destined
for networks not specified in their routing tables, those packets
will be sent to Logical System LS3 for further processing. This configuration
assumes that Logical System LS3 has a connection to an ISP or another
external network.